Texas keeps setting daily records for new coronavirus cases, and doctors in hard-hit Houston are begging residents to take basic safety precautions.

Two nurses at United Memorial Medical Center are being treated for COVID-19, and doctors aren't sure whether they got sick from treating patients or from community spread, reported KHOU-TV.

"I'm doing everything I can to take care of these very sick people, and then you see people out there without a mask, not having social distance, more gatherings all over the place," said chief medical officer Dr. Joseph Varon. "Our biggest frustration is that people are not listening."

The intensive care unit at the Texas Medical Center, the world's largest medical center, is completely full, but officials there said they can add more.

“We are watching numbers increase," said Methodist Hospital CEO Dr. Marc Bloom. "We are seeing more people in the community with the disease, so we know we will need to take care of more individuals. That obviously cannot go on forever, so we need the community to do the right things to bend this curve right now."

All regular ICU beds in the Texas Medical Center are now being used, according to numbers just released on the TMC website, but officials say they can add more.

Hospitals in Houston's Medical Center will now move some ICU patients to beds not normally used for critical care.

Twenty-eight percent of the ICU patients are being treated for COVID-19.

Despite reaching surge capacity, four hospital CEOs said Thursday there's no cause for "unwarranted alarm."

Those same CEOs signed a letter to Houstonians Wednesday warning, "If this trend continues, our hospital system capacity will become overwhelmed."

Dr. Marc Boom explained in a virtual news conference Thursday that the purpose of the letter was to "urge people to do the right things in the community and do so by talking about capacity, but really ended up unintentionally sounding an alarm bell too loudly about capacity."

Texas Gov. Greg Abbott hit pause on the state's reopening after nearly 6,000 new cases were reported Thursday, and he ordered hospitals in Houston and other big cities to suspend non-elective surgeries for the time being.

"The last thing we want to do as a state is go backwards and close down businesses," Abbott said. "This temporary pause will help our state corral the spread until we can safely enter the next phase of opening our state for business."

Businesses that are already allowed to reopen may continue operations under existing health protocols and operating restrictions, but medical providers urged Texans to stay home as much as possible and take basic precautions when going out in public.

"You can be spreading it when you don't even know you have it, and that's kind of the scariest thing about COVID-19," said Kevin McFarlane, an RN and president of the Houston Emergency Nurses Association. "If you're going to be in crowds of going to be with folks, you know, definitely wear a mask."